An embodiment relates generally to identifying anomalies in fault code settings and developing new analytical symptoms based on anomaly analysis to enhance service documents.
Diagnostic software algorithms utilize fault codes or diagnostic trouble codes (DTCs) for aiding technicians in servicing machinery, such as a vehicle at a service department at a dealership. Diagnostic trouble codes (DTCs) are triggered in the vehicle based on diagnostic software algorithms. A service diagnostic tool used by a service or similar retrieves DTCs from a vehicle processor memory that are used to determine the fault in a specific component of the vehicle. Each of the processors in the vehicle includes a memory that stores DTCs when the vehicle experiences an electrical fault. The service technician can review the current triggered DTC or a history of any DTCs for determining the root cause in the vehicle. DTCs are alphanumeric codes that are used to identify a fault that occurs in various components, circuits, or software within the vehicle. Such DTCs are related to various electrical vehicle functions that include, but are not limited to, engine operation, emissions, braking, powertrain, safety, and steering. Each subsystem may have its own on-board processor for monitoring faults of the subsystem operation or a processor may be responsible for monitoring faults for a plurality of subsystems. When the subsystem processor detects a fault, one or more DTCs are generated.
The DTCs assist the service personnel in pinpointing the area of concern. DTCs are retrieved by the service personnel with the aid of a scan tool. Although the DTC provides assistance to the service personnel in pinpointing the area of concern, the DTC does not provide definitive information as to what exactly caused the problem. Usually, a DTC indicates a fault either in a specific component, circuit connecting a component to the control module or in the control module itself. Now, it is still up to the technician to identify the root cause by performing further electrical circuit tests, utilize analytical reasoning, prior experience, or a best guess. Hence, DTCs provides diagnostics only up to certain extent. Additional diagnostic resolution could be obtained only by performing additional field tests and collecting additional operating parameter data from the vehicle. Sometimes, the algorithm generating the DTC may have an error or the calibrations specified in the algorithm are sensitive to vehicle operating conditions which results in triggering a false DTC. In addition, the DTCs may exhibit intermittent behavior which is difficult to fix due to absence of the operating parameters data under which intermittent DTCs were triggered. Intermittent behavior of faults is those instances when a fault is triggered and recorded; however, the fault conditions cannot be replicated at the service repair center.
The scan tool may further retrieve freeze frame operating parameter identifiers (PIDs) that are recorded when a specific DTC is triggered. A PID code is an operating parameter of a component or an output of a diagnostic algorithm that is recorded via the scan tool which is transmitted by reading from the communication bus of the vehicle. One of the devices on the communication bus recognizes the PID code for which it is responsible and returns information relating to the PID code for providing further details relating to one or more of the devices that sense data relating to the detected fault. However, the number of PIDs relating to a DTC may be quite numerous and burdensome to a service personnel having to analyze the PID codes.
In many instances errors are present in the DTC algorithm and DTCs will be triggered under inappropriate preconditions (e.g., conditions for triggering the DTC are improper). Moreover, calibrations may be sensitive based on operating conditions and the operating parameters require re-calibration. With the vast number of PID codes collected and analyzed, anomalies present in the DTC data can be identifiable with the help of statistical and data mining techniques. Anomalies are typically identified when analyzing warranty claim data. However, warranty data is only obtained after a vehicle is in production and claims have been made on the repair. As a result, a vast number of vehicles exhibiting the anomaly in DTCs may have been already serviced. What would be ideal is to identify an anomaly in the DTCs during the development stages or early production stages so that corrective actions can be made during the development stage or early production stage.